Create a forum and set maximum number of attachments to 3 Create a discussion and drag in 3 files to the attachment Quickly drag in another file, whilst the original file upload is still processing Post to the forum Expected result - an error message, just above the attachments area, reading 'You must not attach more than 3 files here.' Note: you can make testing a lot easier by opening up repository/upload/lib.php, finding the 'process_upload' function and adding the line 'sleep(5);' at the start of it, to get the upload script to wait 5 seconds before responding.